1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca> 5 * Copyright (c) 2006 nCircle Network Security, Inc. 6 * All rights reserved. 7 * 8 * This software was developed by Robert N. M. Watson for the TrustedBSD 9 * Project under contract to nCircle Network Security, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by Herb Peyerl. 22 * 4. The name of Herb Peyerl may not be used to endorse or promote products 23 * derived from this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 * 36 * $NetBSD: sysv_ipc.c,v 1.9 1995/06/02 19:04:22 mycroft Exp $ 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_sysvipc.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sem.h> 47 #include <sys/shm.h> 48 #include <sys/ipc.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/ucred.h> 52 53 #ifndef SYSVSHM 54 void (*shmfork_hook)(struct proc *, struct proc *) = NULL; 55 void (*shmexit_hook)(struct vmspace *) = NULL; 56 57 /* called from kern_fork.c */ 58 void 59 shmfork(p1, p2) 60 struct proc *p1, *p2; 61 { 62 63 if (shmfork_hook != NULL) 64 shmfork_hook(p1, p2); 65 return; 66 } 67 68 /* called from kern_exit.c */ 69 void 70 shmexit(struct vmspace *vm) 71 { 72 73 if (shmexit_hook != NULL) 74 shmexit_hook(vm); 75 return; 76 } 77 #endif 78 79 /* 80 * Check for IPC permission. 81 * 82 * Note: The MAC Framework does not require any modifications to the 83 * ipcperm() function, as access control checks are performed throughout the 84 * implementation of each primitive. Those entry point calls complement the 85 * ipcperm() discertionary checks. Unlike file system discretionary access 86 * control, the original create of an object is given the same rights as the 87 * current owner. 88 */ 89 int 90 ipcperm(struct thread *td, struct ipc_perm *perm, int acc_mode) 91 { 92 struct ucred *cred = td->td_ucred; 93 int error, obj_mode, dac_granted, priv_granted; 94 95 dac_granted = 0; 96 if (cred->cr_uid == perm->cuid || cred->cr_uid == perm->uid) { 97 obj_mode = perm->mode; 98 dac_granted |= IPC_M; 99 } else if (groupmember(perm->gid, cred) || 100 groupmember(perm->cgid, cred)) { 101 obj_mode = perm->mode; 102 obj_mode <<= 3; 103 } else { 104 obj_mode = perm->mode; 105 obj_mode <<= 6; 106 } 107 108 /* 109 * While the System V IPC permission model allows IPC_M to be 110 * granted, as part of the mode, our implementation requires 111 * privilege to adminster the object if not the owner or creator. 112 */ 113 #if 0 114 if (obj_mode & IPC_M) 115 dac_granted |= IPC_M; 116 #endif 117 if (obj_mode & IPC_R) 118 dac_granted |= IPC_R; 119 if (obj_mode & IPC_W) 120 dac_granted |= IPC_W; 121 122 /* 123 * Simple case: all required rights are granted by DAC. 124 */ 125 if ((dac_granted & acc_mode) == acc_mode) 126 return (0); 127 128 /* 129 * Privilege is required to satisfy the request. 130 */ 131 priv_granted = 0; 132 if ((acc_mode & IPC_M) && !(dac_granted & IPC_M)) { 133 error = priv_check(td, PRIV_IPC_ADMIN); 134 if (error == 0) 135 priv_granted |= IPC_M; 136 } 137 138 if ((acc_mode & IPC_R) && !(dac_granted & IPC_R)) { 139 error = priv_check(td, PRIV_IPC_READ); 140 if (error == 0) 141 priv_granted |= IPC_R; 142 } 143 144 if ((acc_mode & IPC_W) && !(dac_granted & IPC_W)) { 145 error = priv_check(td, PRIV_IPC_WRITE); 146 if (error == 0) 147 priv_granted |= IPC_W; 148 } 149 150 if (((dac_granted | priv_granted) & acc_mode) == acc_mode) 151 return (0); 152 else 153 return (EACCES); 154 } 155 156 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 157 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 158 void 159 ipcperm_old2new(struct ipc_perm_old *old, struct ipc_perm *new) 160 { 161 162 new->cuid = old->cuid; 163 new->cgid = old->cgid; 164 new->uid = old->uid; 165 new->gid = old->gid; 166 new->mode = old->mode; 167 new->seq = old->seq; 168 new->key = old->key; 169 } 170 171 void 172 ipcperm_new2old(struct ipc_perm *new, struct ipc_perm_old *old) 173 { 174 175 /* XXX: How to handle ID's > USHORT_MAX? */ 176 old->cuid = new->cuid; 177 old->cgid = new->cgid; 178 old->uid = new->uid; 179 old->gid = new->gid; 180 old->mode = new->mode; 181 old->seq = new->seq; 182 old->key = new->key; 183 } 184 #endif 185 186 #ifdef COMPAT_FREEBSD32 187 #include <sys/mount.h> 188 #include <sys/socket.h> 189 #include <compat/freebsd32/freebsd32.h> 190 #include <compat/freebsd32/freebsd32_ipc.h> 191 #include <compat/freebsd32/freebsd32_proto.h> 192 #include <compat/freebsd32/freebsd32_signal.h> 193 #include <compat/freebsd32/freebsd32_syscall.h> 194 #include <compat/freebsd32/freebsd32_util.h> 195 196 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 197 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 198 void 199 freebsd32_ipcperm_old_in(struct ipc_perm_old32 *ip32, struct ipc_perm *ip) 200 { 201 202 CP(*ip32, *ip, cuid); 203 CP(*ip32, *ip, cgid); 204 CP(*ip32, *ip, uid); 205 CP(*ip32, *ip, gid); 206 CP(*ip32, *ip, mode); 207 CP(*ip32, *ip, seq); 208 CP(*ip32, *ip, key); 209 } 210 211 void 212 freebsd32_ipcperm_old_out(struct ipc_perm *ip, struct ipc_perm_old32 *ip32) 213 { 214 215 CP(*ip, *ip32, cuid); 216 CP(*ip, *ip32, cgid); 217 CP(*ip, *ip32, uid); 218 CP(*ip, *ip32, gid); 219 CP(*ip, *ip32, mode); 220 CP(*ip, *ip32, seq); 221 CP(*ip, *ip32, key); 222 } 223 #endif 224 225 void 226 freebsd32_ipcperm_in(struct ipc_perm32 *ip32, struct ipc_perm *ip) 227 { 228 229 CP(*ip32, *ip, cuid); 230 CP(*ip32, *ip, cgid); 231 CP(*ip32, *ip, uid); 232 CP(*ip32, *ip, gid); 233 CP(*ip32, *ip, mode); 234 CP(*ip32, *ip, seq); 235 CP(*ip32, *ip, key); 236 } 237 238 void 239 freebsd32_ipcperm_out(struct ipc_perm *ip, struct ipc_perm32 *ip32) 240 { 241 242 CP(*ip, *ip32, cuid); 243 CP(*ip, *ip32, cgid); 244 CP(*ip, *ip32, uid); 245 CP(*ip, *ip32, gid); 246 CP(*ip, *ip32, mode); 247 CP(*ip, *ip32, seq); 248 CP(*ip, *ip32, key); 249 } 250 #endif 251